Can there be more than one email provider per domain?

No, there's no way to direct [email protected] to a different provider than [email protected].

Alternatives:

• Set up some forwarding. (Like from your website provider to the hosted Exchange provider, after the message has first been received by the former.)

• Use subdomains. (And then set up different DNS records, to make subdomain.example.com refer to a different email provider, to have email for [email protected] be handled differently from [email protected] and [email protected]. Not too nice.)

(An email sender will look up the so-called MX records of your domain. Though one can define multiple records for fallback servers, those will only be used if the primary server does not respond, not if the primary server does not know your email address. Hence: email senders will always try to deliver all email for some domain to the same provider, or will return the message if that fails.)

YES, Multiple PROVIDERS using Split delivery

As long as I've been up with the configuration pages about email routing for Google Apps and Zoho Mail, there are 3 types:

1. Split Delivery: some accounts exist only in one provider and others exist in the other(s) one(s).
2. Dual Delivery: all accounts are supposed to exist in both providers and they are copied to both, non-existing accounts (on the first provider) will bounce.
3. Email Routing: all emails have to arrive to the next provider even when there's no existing account.

In any case your MX records seem to have to be addressed to one email provider and no MX records should be mixed as this answer clearly states (I believe it doesn't matter how many providers you need as long they all support email-routing which is usually a service for paying clients). So what I understand is that your MX records should point to ONE provider (with it's priority alternatives for safety of course), and from that provider you configure the split/dual/route to the next one.

As far as I am testing, Google Apps does allows the MX routing (not in Free legacy panels), and Zoho Mail seems to also allow it but it's been stucked on saving the settings under a Free Panel, I need to test on an panel with a plan.

No, you can have only one mail provider per domain. But there are workaround, if you know what you're doing. I've had an arrangement for a while that worked well, but it was carefully done.

The story was a migration from one hosting/mail provider to another. It involved setting up everything (mailboxes, addresses, groups, etc.) in the new place except for the MX records, so it could receive everything. But it didn't receive anything because the MX was still pointing to the old system. Then the old system was changed so that every mailbox forwarded every message to the new system. Users could then check their mail on either system. Eventually all the users were checking mail in the new system, and the MX was finally switched to the new system, and only from then on all mails went directly to the new system - no longer passed through the old system.

It required careful planning and even more careful setup of the new system. And even so, there were some minor problems because when mails were sent from the new system but the MX was still pointing to the old system, some recipients rejected the messages because they looked spammy.

Summary: Don't mess with this unless you really know what you're doing! If you mess up, it can be really hard to fix, and you are guaranteed to have lost an unknown number of emails to your organisation!